Description & Operation

WARNING: This page is about a different car, the 2000 Ford Windstar and 1999 Ford Windstar. However, it is still accessible from the selected car via links, so may be relevant.

Module communications network consists of several modules working together through 2 module communications networks, referred to as Standard Corporate Protocol (SCP) network and International Standards Organization (ISO) network. SCP and ISO networks provide the ability for module-to-module communications by sharing inputs and outputs instead of each component having to be wired directly to each module. Both networks are connected to the Data Link Connector (DLC) to aid in diagnosing and testing of both networks. This article is used to diagnose SCP and ISO communications network circuit faults.

Modules of the International Standards Organization (ISO) diagnostic communications network are connected to a single wire, or circuit No. 70 (Light Blue/White wire). ISO network will not function if the single wire becomes shorted to ground or voltage. The ISO network modules consist of the Parking Aid Module (PAM), Restraint Control Module (RCM), Left Power Sliding Door Module (LPSDM) and Right Power Sliding Door Module (RPSDM), if equipped.

SCP is a bus network, consisting of a pair of twisted wires to transfer information between all modules. The SCP bus network consists of a twisted pair of wires, positive (+) circuit No. 914 (Tan/Orange wire) and a negative (-) circuit No. 915 (Pink/Light Blue wire), which would allow network communications to continue if one of the bus circuits should fail. The SCP bus network is routed throughout the vehicle to Powertrain Control Module (PCM), Anti-Lock Brake System (ABS) control module, Front Electronics Module (FEM), Rear Electronics Module (REM), Instrument Cluster Module (ICM), Next Generation Speed Control (NGSC) module and Remote Keyless Entry [Driver Door Module] (RKE/DDM) module (if equipped). The following is a listing of all modules of the module communication network, with a brief description of module functions and capabilities. For module locations, see COMPONENT LOCATIONS .

Anti-Lock Brake (ABS)

ABS module is connected to SCP network. ABS module is controls the brake system by regulating brake fluid pressure to prevent wheels from locking and skidding when braking. ABS module also is used for traction control by preventing wheelspin by applying brake fluid pressure to the appropriate front brake and restoring traction when driving in slippery or loose gravel situations.

Front Electronic Module (FEM)

FEM is connected to SCP network. FEM controls power door lock functions for driver's door only, blower motor, front exterior lamps, interior lamps, front and rear windshield wipers. Receives signals from RKE/DDM module and communicates to SCP with Rear Electronic Module (REM).

Instrument Cluster Module (ICM)

ICM is connected to SCP network. ICM displays driver information in the gauges and meters of the instrument cluster. ICM may also contain message center (optional), which displays lamp outage and door/hatch ajar information. Passive Anti-Theft System (PATS) module is integral of the instrument cluster.

Next Generation Speed Control (NGSC) Servo

NGSC servo is connected to SCP network. When activated, NGSC servo controls vehicle speed during cruise control operation.

Passive Anti-Theft System (PATS)

PATS is integral of the Instrument Cluster Module (ICM). PATS is designed to disable vehicle from starting when an unauthorized entry to vehicle is detected.

Powertrain Control Module (PCM)

PCM is connected to SCP network. PCM controls engine performance, emission and on-board diagnostics. For additional information regarding PCM, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

Rear Electronic Module (REM)

REM is connected to SCP network. REM mainly controls the rear portion of vehicle. REM supports other locking features for all passenger doors and Right or Left Power Sliding Door Module (RPSDM/LPSDM) and liftgate. When Power Sliding Door (PSD) operation is requested, REM determines if necessary preconditions are met, and signals the appropriate PSD module for PSD operation (as equipped).

Remote Keyless Entry/Driver Door Module (RKE/DDM)

RKE/DDM is connected to SCP network. RKE/DDM processes signals from remote transmitters and commands from driver's door switches. RKE/DDM also outputs messages through SCP to FEM and REM to either or both LPSPD/RPSDM for left or right power sliding door operation (as equipped).

Restraint Control Module (RCM)

RCM is connected to ISO network, and may also be referred to as an air bag control module. RCM controls the deployment of air bags based on sensor inputs. For additional information see appropriate AIR BAG RESTRAINT SYSTEMS article.

Parking Aid Module (PAM)

PAM is connected to ISO network. PAM controls warning indicators which are triggered by sensors located in the rear bumper. These sensors can advise the vehicle driver of close objects, or out-of-sight objects when reversing the vehicle.

Left/Right Power Sliding Door Module (LPSDM/RPSDM)

LPSDM and/or RPSDM (as equipped) communicate through the ISO network. These PSD modules can send and receive messages from the REM and RKE/DDM modules for desired PSD operations. LPSDM/RPSDM also control automatic opening and closing of left or right power sliding door (if equipped).

Switched System Power (SSP) Feature

SSP feature removes power from relays to prevent excessive draw on vehicle battery. After 30 minutes or more, with all accessories and equipment off, SSP feature removes power to the necessary SSP relays, conserving battery energy. A fault in SSP feature could cause some module communication network functions to be inoperative. Always verify SSP feature is properly operating prior to condemning any component, network or system.